Method for the production of guaiacol.



- ll'ftllTED nnrrs'rn. sotnrnenn, or aonrcn, swrrznanann, nun near/ram:

tutu/"norms, Wisconsin.

nonnative, or"

METHQED 3P0 tiff-IE FROIDUGTXGH F QUAIAGQL,

Ho Drawing.

To all whom may concern:

Be it known that we, Euns'r id. Zonnrnenn and HERMANTN Ronrrmnc, citizens, respectively, of the Republic of Switzerland and the United States, residing. respectively, at Zurich, in the Republic of Switzerland, and

- at Milwaukee, State of Wisconsin, U. S. A,

have invented a certain new and useful Tl provement in Methods for the Production of Guaiacol, of which the following is a full, clear, concise, and exact description.

Our invention relates to a method for producing guaiacol from pyrocatechin. Prior to our invention of the process hereinaf er claimed it was known that pyrocatechin could be methylated by means of methyl sulfuric acid or its alkali salts; for instance, Gorup-Besanez (Ann. 147. 2 17.) has described such a method. Accordin to the Gorup-Besanez method, however, t e yield of guaiacol is so poor that a commercial applieation of said method is not feasible. Ti, however, energetic methylating means are employed, as for instance dimethyl sulfate,

which in view of its exceedingly poisonous qualities is little used for technical purposes, veratrol is produced in great quantities. (Ulhnann Amt. 327. 10 i, Per/ 0in and Weds mama Zentmlblatt 07. i; 406.)

We have found that when pyrocatechin and potassium methyl sulfate are intimately mixed and melted in the presence of veratrol guaiacol is produced in considerable quantities provided a weak alkaline compound, such as carbonate or bicarbonate of sodium is gradually added to the mixture. The great advantage of this method is obvious when consideration is given to the fact that pyrocatechin is inclined to undergo considerable changes in alkaline watery solutions. This method whereby we methylate pyrocatechin in veratrol as a solvent at a temperature of 180 degrees has the advantage that only one hydroxyl' group is methylated in a yield exceeding 85 per cent. The folmama Specification of Eetters Patent.

net, as, rare.

' application filed January 8, 153.7". ijerialfio. lancer. i

lowin exam is will sufficientl illustrateour improved method.

Eammple.

11 grams of pyrocatechin are intimately grated with 25 grams of potassium methyl sulfate and mixed with 15 grams of vera-' trol. To this mixture 25 grams of sodium bicarbonate is added in portions during two hours at a temperature of 169 to 180 degrees. Upon getting cold, the reaction product is acidified and subjected to a steam distillation. From this distillate the guaiacol as well as the unchanged veratrol is recovered, according to known methods. The yield of guaiaccl amounts to 10.5 grams.

What we claim as new and desire to secure by Letters Patent of the United States is: v

1. The herein described method of producing guaiacol from pyrocatechin, which comprises subjecting the pyrocatechin to the action of an alkali salt of methyl sulfuric acid in the presence of veratrol, and adding a weak alkali metal compound to the material under treatment, while the mixture is held at a temperature of substantially 160 to 180 degrees.

. 2. The herein described method of producing guaiacol, which comprises subjecting pyrocatechin to the action of a methylating agent, in the presence or veratrol, and adding a weal: alkali metal compound.

3, The method of producing guaiacol from pyrocatechin which comprises subjecting the pyrccatechin to the action of a methylating agent in the presence or veratrol at a tempyrocatechin which comprises subjecting the pyrocatechin to the action of a salt of methyl sulfuric acid in the presence of veratrol, adding a weakly alkaline compound while the mixture is held at a temperature of substantially 160 to 180' degrees coclin and acidifying the reaction product, distil ating the reaction product and separating the guaiacol from the distillate.

5. The herein described method of proweakly alkaline compound while the mixture 10 is maintained at a temperature causing a reaction of the methylating agent with the pyrocatechin.

In W1tness whereof ERNST H ZOLLINGER has hereunto subscribed his name this 14th day of March, A. D. 1917.

' ERNST H. ZOLLINGER. In witness whereof HERMANN ROEHLING has hereunto subscribed his name this 5 day of May, A. D. 1917. HERMANN BOEHLING.

Oopies of this patent may be obtained tor five cents each, by addressing the fGommissioner o1 Batents,

' Washington, D. 0. i 

